The present disclosure relates to an automotive powertrain unit.
Japanese Unexamined Patent Publication No. 2016-65465 discloses an example of an engine included in an automotive powertrain unit. Specifically, Japanese Unexamined Patent Publication No. 2016-65465 discloses an engine including an external exhaust gas recirculator (EGR) connected to an intake passage and an exhaust passage. As illustrated in FIG. 1 of the publication, the EGR is provided to an end of the engine along the engine output shaft.
When the automotive powertrain unit is overhauled (in particular, a valve system of the engine is overhauled), the cylinder head may be removed from the engine. Even though the engine is mounted in the vehicle, such overhaul service needs to be carried out smoothly.
Meanwhile, the EGR disclosed in the Japanese Unexamined Patent Publication No. 2016-65465 is usually supported by the cylinder head. However, when the cylinder head is to be removed for the overhaul service, such a configuration requires the EGR to be removed in advance from the cylinder head.
The EGR includes multiple devices such as an EGR passage connecting an exhaust passage and an intake passage of the engine, and an EGR cooler for cooling burned gas. Hence, removing the EGR from the cylinder head takes time, and thus is inconvenient for smooth overhaul of the engine. In such a case, a space is required to store the removed EGR. In view of this extra space required, the EGR has room for improvement for smooth overhaul service.
The EGR could be supported by the vehicle body. However, considering that the EGR is connected to both the intake passage and the exhaust passage, such a support structure could transmit a vibration caused by an operation of the engine to the automotive body through the EGR when the vibration enters the EGR through the intake passage and the exhaust passage. The transmission of the vibration deteriorates noise vibration and harshness (NVH) characteristics of the vehicle, and is not preferable.
The present disclosure is conceived in view of the above problems, and intends to improve serviceability of an automotive powertrain unit without deteriorating NVH characteristics.